Means for producing mechanical drafts



Feb. 2 17926. 41,571,797'

G. J. A. l.. PRAT MEANS FOR PRODUGING MECHANICAL DRAFTS- Filed Feb. 28. 1924 k A 374W M d j/f v TW IE 3110014450@ @was JP/ m @www L Cltbozwu;

Patented Feb. 2, i926.

arras GEORGES JULES ARMAND LOUS PRAT, OF PARIS, FRANCE.

MEANS FOR PRODUCING MECHANCAL DRAFTS.

Application filed February 255, 1924. Serial No. 695,870.

To @ZZ whom t may concern Be it known that I, GEORGES JULES AR- MAND LoUts PRAT, citizen of the French Republic, residing at 144 Avenue des Champs Elyses, at Paris, Department of Seine, France, have invented certain new and useful Improvements in Means for Producing` Mechanical Drafts, of which the following` is a specification.

This invention relates to mechanical draft produced by means of two fans, and has for its object so to construct a plant provided with inechanisal draft that it responds better than has hitherto been the case to the requirements and working' conditions with respect to the firing;` thereof.

The essential feature of the invention consists in combining with two fans for produringsuction or blowing' action, and which are associated together and located at the base of the chimney of a plant provided with mechanical draft and havingan ejector nozzle, common to the two fans-three shutters which are pivotally mounted upon axes parallel to the axes of the rotors of the fans one of the shutters constituting; the common wall which separates the delivery outlets of the fans and the two othershutters forming the outer walls of the said outlets: the said shutters being so constructed and arranged that by modifyino' their position, the section of the delivery outlet or outlets may be varied so that an induced draft can be obtained with one or two fans, a forced draft can be obtained with one or two fans, or a natural draft can be obtained.

The invention includes, in addition to the principal features and arrangements just mentioned other arrangements which will be more fully described hereafter.

It comprises certain constructional embodiments and various applications of the improvements, as well as special parts suitable for the construction of a plant embodying the improvements.

In order that the invention may be clearly understood, it will now be described with reference to the accompanying drawings, but it is to be understood that the description and drawing are given merely by way of example.

Figs. 1 and 2 of the drawing are both diagrammatic vertical sections of the same plant adapted to enable mechanical draft to be obtained and constructed according to the invention,l certain of the operative parts being shown in different relative positions in the two figures.

Fig 3 is a diagrammatic section on the line 3-3, F ig. 2, looking` downwardly.

.ln providing a plant to obtain mechanical draft as shown in the drawings, the structure employed is substantially as follows zM The plant comprises a base or pedestal a, the bottom of which is connected to the smole conduit from a boiler furnace or other apparatus (not shown).

Z is a chimney connected to the base, and in the axis of the chimney is located the ejectotl or delivery nozzle c. The plant also comprises two suction or blowing` fans which are furnished with axially located inlet openings in their opposite sides, and the fans may be identicalin construction. rlhe fans are provided with volutes cZ and e and rotors j" and g. rlhey are adapted to be mounted suitably in the base associated together and arranged for instance back to back as re- `gards the axis of their delivery outlets. Appropriate spaces are left between the side walls L and of the fans and the respective side walls y' of the base to admit smoke or gases which enter the base to the inlet openings in the side walls of the fans, as is indicated by the arrows in Figs. 1 and 2.

Instead of rovidin,f the fans with xed elements parallel to the axes of their rotors to constitute the walls of the fan delivery outlets, they are provided with movable elements constituted by shutters 7c, Z and m which are pivotally mounted at their lower edges.

The shutter Z occupies the plane of separation between the fan outlets at the point where the volutes meet. It is carried by a spindle Z parallel to the axes of the rotors of the fans.

The two other shutters ,le and m are mounted respectively on the outer peripheral walls of said volutes, spindles 761 and-ml being provided for the purpose parallel to the previously mentioned spindle.

The shutters are operated from the outside by any appropriate means.

lith the foregoing arrangement induced draft can be obtained when the shutters and m occupy the position shown at Fig. 1, that is to say with the space open betweenI the lower edge of the delivery nozzle c and the chimney ZJ. The shutter Z` may either occupy the position shown at Fig. 1, one fan delivering into the nozzle and functioning alone, or else it may occupy a symmetrical position on the other side of the axis of the chimney, the other fan then functioning alone. Ur again it may occupy a position in which it divides the nozzle into two equal portions so that the two fans operate concurrently.

Natural draft is obtained when the shutters and in occupy the same position as stated above, whilst the shutter Z is in a central vertical position.

Aspirated draft is obtained when the shutters 7c and m occupy' the positions shown at Figs. 2 and 3, that is to say when they close direct communication between the base and the chimney. The shutter Z is set either into the central vertical position in the axis of the chimney, in which it is shown in Fig. Q, with the two fans working together: or it may be set into a position in which it causes one or other of the fans alone to deliver into the base of the nozzle, the fan effecting this delivery working alone.

It is to be clearly understood, as has al ready been intimated that the invention not limited to the particular' construction which has been illustrated above, but that all modifications are included fallingl within a fair interpretation of the claims.

In some instances the fans may have a single inlet opening at one side thereof and may be n'iounted with its outer side wall against the corresponding side wall of the base a.

VJhat l claim as my invention and desire to secure by Letters Patent of the United States of America iszl. ln a plant for working with mechanim cal draft, the combination of a chamber, an inlet passage for smoke or the like to the said chamber, a chimney leading from the said chamber, two rotary fans mounted within the said chamber, casings to the said fans such casings being provided with a per foration, outlets from the said casings to the. chamber, the said outlets opening contiguous to one another, a nozzle located in the axis of the chimney and leaving a space between its outer wall and the inner surface of the chimney and three pivoted shutters, one of which is mounted upon a pivot between the outlets of the fans and the other two of which are pivoted respectively to the other sides of the said outlet, for the purposes set forth. 1 l

2. In a plant for Working with mechanical draft, the combination of a chamber, an inlet passage for smoke or the like to the said chamber, a chimney leading from the said chamber, two rotary fans mounted within the said chamber, volute shaped casings to the said fans provided with openings directed towards the chimney, side plates to the said casings provided with at least one inlet orifice, a nozzle mounted within the said chimney and leaving` a space between the outer surface thereof and the said chimney, and three pivoted shutters one of which is pivoted between the outlet openings of 'the volutes of the fans andis adapted to be set in a vertical position or swung to either side, the other two pivoted shutters beingl pivoted to the opposite sides of the openings of the volutes to the central shutter and being adapted to register substantially with the direction of the outer walls of the nozzle er to rest against the side walls of the chamber at the base of the chimney, sub-- stantially as and for the purposes set forth.

In testimony whereof I have hereunto set my hand.

GEORGES JULES ARMAND LOUS PRAT. 

